Vinyl pool - 22k gal => PF=5.5

Im a bit confused about why I cannot get any free chlorine count 0 FC. I drop 1 bag of shock per day. Water color is clear with no organic matter on the bottom. Walls are not slimy. I checked my test chemicals with pool store check came out the same. I do get 100% sun from morning to dusk. Its been hot here on the east coast last week. 90F.

If I drop 2 bags of shock I will get a low TAC count for about 1 day.


FC:0 TAC:0 CH:200 CYA:70 TA:90 PH:7